Patent EP-4099381-A2 (EP)
Title: Member connection method by means of a copper sintered film with a plurality of radially arranged regions and a plurality of concentrically arranged regions
Inventor: NEGISHI MOTOHIRO
IPC: H01L23/488
Filed: 2018-10-23
Abstract: A member connection method for connecting a first member and a second member by means of a copper sintered compact includes: a printing step of forming a coating film (8) of a copper paste for connection in a connection region (5) of respective members (2) and (3) into a predetermined print pattern (9); a lamination step of laminating the respective members (2) and (3) with the coating film (8) interposed therebetween; and a sintering step of sintering the coating film (8) to form a copper sintered compact (4) and connecting the respective members (2) and (3) by means of this copper sintered compact (4), in which in the printing step, a coating film-formed region (10) in which the coating film (8) is formed and a coating film non-formed region (20) in which the coating film (8) is not formed are formed in the print pattern (9), and the coating film-formed region (10) is divided into a plurality of radial regions (12a) to (12c) and a plurality of concentric regions (13a) and (13b) by means of a plurality of line-shaped regions (21a) to (21c) provided so as to connect various points A to D which are separated apart from one another in the marginal part (6) of the connection region (5). The connection region (5) may be a rectangular-shaped region, and the coating film-formed region (10) may include regions disposed correspondingly to the corners (R1) to (R4) of the connection region (5). The plurality of the regions (12a-12c, 13a-13b) in the coating film-formed region (10) may have larger areas as the regions (12a-12c, 13a-13b) are disposed at positions closer to the marginal part of the connection region (5). In an embodiment, the coating film-formed region (10) includes division regions (11) and corner regions (14), wherein the division regions (11) include radial regions (12), concentric regions (13) and corner vicinity regions (19). Examples of the respective members (2) and (3) include semiconductor elements such as an IGBT, a diode, a Schottky barrier diode, an MOS-FET, a thyristor, a logic circuit, a sensor, an analog integrated circuit, an LED, a semiconductor laser, and a transmitter; substrates for mounting semiconductor elements such as a lead frame, a metal plate-attached ceramic substrate (for example, a DBC), and an LED package; members for power feeding such as a copper ribbon, a metal block, and a terminal; a heat radiation plate; and a water cooling plate. The copper paste for connection includes metal particles and a dispersing medium, wherein the metal particles may include submicron copper particles (of various shapes, preferably of a spherical shape, an approximately spherical shape or a flake shape), micro-copper particles (of various shapes, preferably of a flake shape) and other metal particles, for example, particles of nickel, silver, gold, palladium or platinum. In this member connection method, since a plurality of regions in the coating film-formed region (10) includes regions that are arranged radially (12a-12c) and regions that are arranged concentrically (13a-13b), it is possible to efficiently release air out of the connection region (5) by means of the coating film non-formed region (10) while uniformly expanding the coating film (8) in the connection region (5). Therefore, a void-suppressing effect can be sufficiently secured.